Accept No Substitutes
by Hazel-Beka
Summary: Iruka explains to his boyfriend why barrier seals and condoms are not interchangeable. Kakashi/Iruka


**Accept No Substitutes**

Kakashi pressed his fingers in deeper and Iruka let out a fluttering sigh before pulling him down to bite at his lips. When Kakashi thrust his fingers in again, Iruka bucked up, grinding against his hip, and Kakashi licked the moan out of his mouth.

"Fuck me," Iruka said, in a tone caught between a demand and a plea.

Kakashi kissed him again, and then slid his fingers out and squeezed Iruka's thigh.

"I intend to. Just let me get a condom."

The lube was already sitting on the bedside table, and Kakashi dropped it onto the bed beside Iruka's hip before reaching into the open drawer and seeking out the foil square by touch alone. After a couple of seconds, he frowned and shifted so that he could peer into the drawer, rummaging more hurriedly through the contents.

"Hurry up."

Kakashi stroked a thumb absently over Iruka's wrist, continuing to delve through the drawer with his other hand. It was no use. In a last act of desperation he opened his sharingan eye, but even if it had possessed condom-seeking vision, it still would have been a wasted effort. There wasn't a single foil packet in the drawer.

"Shit," Kakashi muttered. "I swear I had a million of those things."

"You had six," Iruka corrected. "Are you telling me you don't have any condoms? Because we're not doing this without one."

Kakashi stared at him, appalled, and Iruka gave him a stern and exasperated expression, which didn't help because Kakashi secretly found it extremely attractive, especially when instead of being directed at him from across the Mission Desk, it came from a naked Iruka lying in his bed.

"Please? Just one time."

Iruka slapped his hand away from where it had been sneaking towards the lube.

"We've been sleeping together for less than two weeks. I am not going to have unprotected sex with you until we've both been tested and cleared. That is non-negotiable."

"But..."

"No buts."

 _Not even yours_ , Kakashi thought sadly.

"You should have bought more," Iruka chided, even as he pressed his thigh against Kakashi's.

"But how did we manage to use all of my million condoms –"

"Your six condoms," Iruka muttered.

"– in less than two weeks?"

Iruka sighed and sat up. He ran a hand through Kakashi's hair and placed an open-mouthed kiss on his shoulder.

"Well, we used two on the first night we got together," he murmured by Kakashi's ear, tracing a thumb along Kakashi's collarbone. "And then there was the time in the bathroom. And the kitchen." His hand moved down over Kakashi's chest, tracing the muscles and skirting the hard planes of his abdomen. "And two more last weekend when I stayed over. That was a _good_ weekend."

"The best weekend," Kakashi agreed.

"We'll have better ones," Iruka promised, his voice low and throaty now. His hand reached the top of Kakashi's thigh and lightly stroked the dip beneath his pelvic bone, moving inwards. "But we did a lot of things over those two days that didn't need condoms at all. Do you remember?"

Kakashi could do one better – he had total recall of every moment, courtesy of the sharingan. It had drained him more than he would ever admit, but it had been worth it.

"I remember that thing you did with your mouth."

Iruka smiled and pressed a kiss beneath his ear. "Then how about I...?"

"Still want to fuck you," Kakashi said.

Iruka sat back and glared at him, pointedly removing his hand.

"Is the word 'non-negotiable' too long for you to grasp?"

"You said unprotected sex was non-negotiable," Kakashi said. "But while you were trying to seduce me, I was thinking."

The pillow smacked him across the face before he'd even registered that Iruka had moved. Kakashi couldn't help but admire his reflexes. Maybe he should recommend Iruka for jounin, although filling out the paperwork might get a bit awkward.

"I was thinking about having sex with you," he clarified.

Iruka lowered the pillow, but didn't let go of it.

"Wouldn't it kill the mood a bit to go and buy some?" he asked. "Assuming you know a place that sells condoms at this time of night."

Kakashi, in fact, knew of two such places. He decided not to mention this.

"I wasn't going to go buy some. I was using my highly trained problem solving skills to think of a substitute."

Iruka gave him a blank stare. "A substitute."

"Something we could use instead of a condom," Kakashi said.

Iruka gave him a look of fascinated horror.

"You can't just – You can't just use any old thing that fits over your dick! Damnit, Kakashi, this isn't a training exercise where you have to build a shelter from limited resources. This is _sex_. You can't – What the hell were you even thinking of using?"

"I'm glad you asked," Kakashi said. "I was thinking: what are the most important features of a condom? They have to be strong, flexible and impermeable."

"And cock-shaped," Iruka added.

"And approximately the right size and shape for my cock," Kakashi agreed. "But with what I'm thinking of, we can make it fit." Iruka looked alarmed at this. Kakashi couldn't think why.

He leaned over to root through the drawer of the bedside table again. "We have the materials right here." With a flourish, he withdrew a small slip of paper and held it out proudly. Iruka stared at it.

"Is that some of my chakra paper?" It was. While Kakashi liked to read before going to bed, Iruka preferred to sit and create explosive tags that could destroy Kakashi's whole apartment building with the tiniest trickle of chakra. Kakashi found the habit endearing.

"A condom," Kakashi said, "is basically a _barrier_ , after all."

Iruka let out a sound that could have been a laugh but could also have been the last of his faith in humanity escaping.

"You," he said, and then paused. Kakashi waited. "You want me to put a barrier seal _on your dick_ and then let you _fuck me with it_?"

"Maa, you don't have to put the actual seal on me. You're good enough to direct the barrier where you want it to go, and shape it how you want, right?"

"That's. You." Iruka gestured helplessly.

"Oh," Kakashi said, realising what the problem was. "You didn't leave your inks here, but I have a pen." He reached back into the drawer and withdrew a blue ballpoint, the end slightly chewed.

Iruka had been wrestling with his expression, but now he settled on a look of abject horror. "You want me to draw a seal with a _ballpoint_?"

"Is that...not OK?"

Iruka looked as though Kakashi had suggested they murder a small child and fashion a condom out of its skin.

"It's not quite the same as a calligraphy brush, is it?" he asked. Kakashi took pity on the ballpoint and put it back in the drawer, safe from Iruka's disgusted stare. "More to the point, we cannot and _will not_ use a barrier seal instead of a condom."

"But why?" Kakashi whined.

Iruka threw up his hands. "Because it's not the same thing! There are absolutely no sexual applications of barrier seals." He let his hands drop and shook his head. "I cannot believe we are actually having this conversation."

"Can't you just try it? Please?"

He fluttered the paper and Iruka eyed it with distaste. "Kakashi, barrier seals are enforced on the _outside_ , not the _inside_. And to keep it in the right place while it's moving somewhere I can't even see would take an incredible amount of concentration."

"You could feel it," Kakashi pointed out.

"That's probably another negative. Barriers aren't made so that you can feel things through them. And, you know, even if we somehow managed to have really shitty sex like that, you can't pull off a barrier seal and tie a knot in the end. I'd have to drop the barrier and there'd be a mess. It would go everywhere."

Kakashi sat back on his heels and thoughtfully measured up the pros and cons. It was a tough call.

"Kakashi," Iruka snapped. "We are _not_ using a barrier seal. Get that through your stupid genius head."

Kakashi sighed and put the chakra paper back in the drawer. Time for Plan B.

"Well, we could always murder a small child and then peel off its skin –"

Iruka gave him a look that Kakashi thought would have been more fitting if he'd suggested that Iruka draw a seal in ballpoint pen.

"No," he said flatly.

"I think I have an unpaired sock somewhere at the bottom of my drawer..."

Iruka raised the pillow again and Kakashi moved back so hastily he almost fell off the bed.

"You have two options," Iruka said. "You can either stop talking and we can do something that doesn't involve you fucking me but does involve mind-blowing orgasms, or you can stop talking and we go straight to sleep. Your choice."

Kakashi was still disappointed that his stroke of genius was being so cruelly dismissed, but on the other hand, Iruka was still in his bed, naked, half-hard and wonderfully creative. It would be a crime to let that go to waste.

"So," Kakashi said. "That thing with your tongue."

Iruka smiled and pushed him down onto the bed.


End file.
